gpt: Support for GPT (GUID Partition Table) restoration

The restoration of GPT table (both primary and secondary) is now possible.
Function 'gpt_restore' presents example of partition restoration process.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Piotr Wilczek <p.wilczek@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
This commit is contained in:
Lukasz Majewski 2012-12-11 11:09:46 +01:00 committed by Tom Rini
parent fae2bf22a2
commit 40684ddb83
2 changed files with 330 additions and 3 deletions

View File

@ -37,6 +37,8 @@
#include <part_efi.h>
#include <linux/ctype.h>
DECLARE_GLOBAL_DATA_PTR;
#if defined(CONFIG_CMD_IDE) || \
defined(CONFIG_CMD_SATA) || \
defined(CONFIG_CMD_SCSI) || \
@ -62,13 +64,10 @@ static inline u32 efi_crc32(const void *buf, u32 len)
static int pmbr_part_valid(struct partition *part);
static int is_pmbr_valid(legacy_mbr * mbr);
static int is_gpt_valid(block_dev_desc_t * dev_desc, unsigned long long lba,
gpt_header * pgpt_head, gpt_entry ** pgpt_pte);
static gpt_entry *alloc_read_gpt_entries(block_dev_desc_t * dev_desc,
gpt_header * pgpt_head);
static int is_pte_valid(gpt_entry * pte);
static char *print_efiname(gpt_entry *pte)
@ -114,6 +113,7 @@ static inline int is_bootable(gpt_entry *p)
sizeof(efi_guid_t));
}
#ifdef CONFIG_EFI_PARTITION
/*
* Public Functions (include/part.h)
*/
@ -225,6 +225,281 @@ int test_part_efi(block_dev_desc_t * dev_desc)
return 0;
}
/**
* set_protective_mbr(): Set the EFI protective MBR
* @param dev_desc - block device descriptor
*
* @return - zero on success, otherwise error
*/
static int set_protective_mbr(block_dev_desc_t *dev_desc)
{
legacy_mbr *p_mbr;
/* Setup the Protective MBR */
p_mbr = calloc(1, sizeof(p_mbr));
if (p_mbr == NULL) {
printf("%s: calloc failed!\n", __func__);
return -1;
}
/* Append signature */
p_mbr->signature = MSDOS_MBR_SIGNATURE;
p_mbr->partition_record[0].sys_ind = EFI_PMBR_OSTYPE_EFI_GPT;
p_mbr->partition_record[0].start_sect = 1;
p_mbr->partition_record[0].nr_sects = (u32) dev_desc->lba;
/* Write MBR sector to the MMC device */
if (dev_desc->block_write(dev_desc->dev, 0, 1, p_mbr) != 1) {
printf("** Can't write to device %d **\n",
dev_desc->dev);
free(p_mbr);
return -1;
}
free(p_mbr);
return 0;
}
/**
* string_uuid(); Convert UUID stored as string to bytes
*
* @param uuid - UUID represented as string
* @param dst - GUID buffer
*
* @return return 0 on successful conversion
*/
static int string_uuid(char *uuid, u8 *dst)
{
efi_guid_t guid;
u16 b, c, d;
u64 e;
u32 a;
u8 *p;
u8 i;
const u8 uuid_str_len = 36;
/* The UUID is written in text: */
/* 1 9 14 19 24 */
/* xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx */
debug("%s: uuid: %s\n", __func__, uuid);
if (strlen(uuid) != uuid_str_len)
return -1;
for (i = 0; i < uuid_str_len; i++) {
if ((i == 8) || (i == 13) || (i == 18) || (i == 23)) {
if (uuid[i] != '-')
return -1;
} else {
if (!isxdigit(uuid[i]))
return -1;
}
}
a = (u32)simple_strtoul(uuid, NULL, 16);
b = (u16)simple_strtoul(uuid + 9, NULL, 16);
c = (u16)simple_strtoul(uuid + 14, NULL, 16);
d = (u16)simple_strtoul(uuid + 19, NULL, 16);
e = (u64)simple_strtoull(uuid + 24, NULL, 16);
p = (u8 *) &e;
guid = EFI_GUID(a, b, c, d >> 8, d & 0xFF,
*(p + 5), *(p + 4), *(p + 3),
*(p + 2), *(p + 1) , *p);
memcpy(dst, guid.b, sizeof(efi_guid_t));
return 0;
}
int write_gpt_table(block_dev_desc_t *dev_desc,
gpt_header *gpt_h, gpt_entry *gpt_e)
{
const int pte_blk_num = (gpt_h->num_partition_entries
* sizeof(gpt_entry)) / dev_desc->blksz;
u32 calc_crc32;
u64 val;
debug("max lba: %x\n", (u32) dev_desc->lba);
/* Setup the Protective MBR */
if (set_protective_mbr(dev_desc) < 0)
goto err;
/* Generate CRC for the Primary GPT Header */
calc_crc32 = efi_crc32((const unsigned char *)gpt_e,
le32_to_cpu(gpt_h->num_partition_entries) *
le32_to_cpu(gpt_h->sizeof_partition_entry));
gpt_h->partition_entry_array_crc32 = cpu_to_le32(calc_crc32);
calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
le32_to_cpu(gpt_h->header_size));
gpt_h->header_crc32 = cpu_to_le32(calc_crc32);
/* Write the First GPT to the block right after the Legacy MBR */
if (dev_desc->block_write(dev_desc->dev, 1, 1, gpt_h) != 1)
goto err;
if (dev_desc->block_write(dev_desc->dev, 2, pte_blk_num, gpt_e)
!= pte_blk_num)
goto err;
/* recalculate the values for the Second GPT Header */
val = le64_to_cpu(gpt_h->my_lba);
gpt_h->my_lba = gpt_h->alternate_lba;
gpt_h->alternate_lba = cpu_to_le64(val);
gpt_h->header_crc32 = 0;
calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
le32_to_cpu(gpt_h->header_size));
gpt_h->header_crc32 = cpu_to_le32(calc_crc32);
if (dev_desc->block_write(dev_desc->dev,
le32_to_cpu(gpt_h->last_usable_lba + 1),
pte_blk_num, gpt_e) != pte_blk_num)
goto err;
if (dev_desc->block_write(dev_desc->dev,
le32_to_cpu(gpt_h->my_lba), 1, gpt_h) != 1)
goto err;
debug("GPT successfully written to block device!\n");
return 0;
err:
printf("** Can't write to device %d **\n", dev_desc->dev);
return -1;
}
int gpt_fill_pte(gpt_header *gpt_h, gpt_entry *gpt_e,
disk_partition_t *partitions, int parts)
{
u32 offset = (u32)le32_to_cpu(gpt_h->first_usable_lba);
ulong start;
int i, k;
size_t name_len;
#ifdef CONFIG_PARTITION_UUIDS
char *str_uuid;
#endif
for (i = 0; i < parts; i++) {
/* partition starting lba */
start = partitions[i].start;
if (start && (start < offset)) {
printf("Partition overlap\n");
return -1;
}
if (start) {
gpt_e[i].starting_lba = cpu_to_le64(start);
offset = start + partitions[i].size;
} else {
gpt_e[i].starting_lba = cpu_to_le64(offset);
offset += partitions[i].size;
}
if (offset >= gpt_h->last_usable_lba) {
printf("Partitions layout exceds disk size\n");
return -1;
}
/* partition ending lba */
if ((i == parts - 1) && (partitions[i].size == 0))
/* extend the last partition to maximuim */
gpt_e[i].ending_lba = gpt_h->last_usable_lba;
else
gpt_e[i].ending_lba = cpu_to_le64(offset - 1);
/* partition type GUID */
memcpy(gpt_e[i].partition_type_guid.b,
&PARTITION_BASIC_DATA_GUID, 16);
#ifdef CONFIG_PARTITION_UUIDS
str_uuid = partitions[i].uuid;
if (string_uuid(str_uuid, gpt_e[i].unique_partition_guid.b)) {
printf("Partition no. %d: invalid guid: %s\n",
i, str_uuid);
return -1;
}
#endif
/* partition attributes */
memset(&gpt_e[i].attributes, 0,
sizeof(gpt_entry_attributes));
/* partition name */
name_len = sizeof(gpt_e[i].partition_name)
/ sizeof(efi_char16_t);
for (k = 0; k < name_len; k++)
gpt_e[i].partition_name[k] =
(efi_char16_t)(partitions[i].name[k]);
debug("%s: name: %s offset[%d]: 0x%x size[%d]: 0x%lx\n",
__func__, partitions[i].name, i,
offset, i, partitions[i].size);
}
return 0;
}
int gpt_fill_header(block_dev_desc_t *dev_desc, gpt_header *gpt_h,
char *str_guid, int parts_count)
{
gpt_h->signature = cpu_to_le64(GPT_HEADER_SIGNATURE);
gpt_h->revision = cpu_to_le32(GPT_HEADER_REVISION_V1);
gpt_h->header_size = cpu_to_le32(sizeof(gpt_header));
gpt_h->my_lba = cpu_to_le64(1);
gpt_h->alternate_lba = cpu_to_le64(dev_desc->lba - 1);
gpt_h->first_usable_lba = cpu_to_le64(34);
gpt_h->last_usable_lba = cpu_to_le64(dev_desc->lba - 34);
gpt_h->partition_entry_lba = cpu_to_le64(2);
gpt_h->num_partition_entries = cpu_to_le32(GPT_ENTRY_NUMBERS);
gpt_h->sizeof_partition_entry = cpu_to_le32(sizeof(gpt_entry));
gpt_h->header_crc32 = 0;
gpt_h->partition_entry_array_crc32 = 0;
if (string_uuid(str_guid, gpt_h->disk_guid.b))
return -1;
return 0;
}
int gpt_restore(block_dev_desc_t *dev_desc, char *str_disk_guid,
disk_partition_t *partitions, int parts_count)
{
int ret;
gpt_header *gpt_h = calloc(1, sizeof(gpt_header));
if (gpt_h == NULL) {
printf("%s: calloc failed!\n", __func__);
return -1;
}
gpt_entry *gpt_e = calloc(GPT_ENTRY_NUMBERS, sizeof(gpt_entry));
if (gpt_e == NULL) {
printf("%s: calloc failed!\n", __func__);
free(gpt_h);
return -1;
}
/* Generate Primary GPT header (LBA1) */
ret = gpt_fill_header(dev_desc, gpt_h, str_disk_guid, parts_count);
if (ret)
goto err;
/* Generate partition entries */
ret = gpt_fill_pte(gpt_h, gpt_e, partitions, parts_count);
if (ret)
goto err;
/* Write GPT partition table */
ret = write_gpt_table(dev_desc, gpt_h, gpt_e);
err:
free(gpt_e);
free(gpt_h);
return ret;
}
#endif
/*
* Private functions
*/

View File

@ -176,10 +176,62 @@ int test_part_amiga (block_dev_desc_t *dev_desc);
#endif
#ifdef CONFIG_EFI_PARTITION
#include <part_efi.h>
/* disk/part_efi.c */
int get_partition_info_efi (block_dev_desc_t * dev_desc, int part, disk_partition_t *info);
void print_part_efi (block_dev_desc_t *dev_desc);
int test_part_efi (block_dev_desc_t *dev_desc);
/**
* write_gpt_table() - Write the GUID Partition Table to disk
*
* @param dev_desc - block device descriptor
* @param gpt_h - pointer to GPT header representation
* @param gpt_e - pointer to GPT partition table entries
*
* @return - zero on success, otherwise error
*/
int write_gpt_table(block_dev_desc_t *dev_desc,
gpt_header *gpt_h, gpt_entry *gpt_e);
/**
* gpt_fill_pte(): Fill the GPT partition table entry
*
* @param gpt_h - GPT header representation
* @param gpt_e - GPT partition table entries
* @param partitions - list of partitions
* @param parts - number of partitions
*
* @return zero on success
*/
int gpt_fill_pte(gpt_header *gpt_h, gpt_entry *gpt_e,
disk_partition_t *partitions, int parts);
/**
* gpt_fill_header(): Fill the GPT header
*
* @param dev_desc - block device descriptor
* @param gpt_h - GPT header representation
* @param str_guid - disk guid string representation
* @param parts_count - number of partitions
*
* @return - error on str_guid conversion error
*/
int gpt_fill_header(block_dev_desc_t *dev_desc, gpt_header *gpt_h,
char *str_guid, int parts_count);
/**
* gpt_restore(): Restore GPT partition table
*
* @param dev_desc - block device descriptor
* @param str_disk_guid - disk GUID
* @param partitions - list of partitions
* @param parts - number of partitions
*
* @return zero on success
*/
int gpt_restore(block_dev_desc_t *dev_desc, char *str_disk_guid,
disk_partition_t *partitions, const int parts_count);
#endif
#endif /* _PART_H */